Quantitative tick drag samples were taken at various times during the day and night from February through April 1994 on St. Catherines Island or on Sapelo Island, Georgia. For each month, there was no statistical difference between the numbers of adult blacklegged ticks, Ixodes scapularis, collected during any hour of daylight or darkness on St. Catherines Island, Adult I. scapularis also quested during both day and night on Sapelo Island, but on this island significantly more ticks were collected in 1 nocturnal sample during March. Nocturnal questing may partially explain why hosts that are principally nocturnal or that are active during both day and night are often heavily parasitized by adult I. scapularis. This observation could be epidemiologically important with respect to tickborne zoonoses such as Lyme disease and babesiosis.